


The Usual Suspects

by LadyLini



Category: Castle, Supernatural
Genre: Crossover, Crossovers & Fandom Fusions, F/M, M/M, Supernatural - Freeform, Supernatural/Castle, Supernatural/Castle Crossover, castle - Freeform
Language: English
Status: Completed
Published: 2015-04-02
Updated: 2015-04-02
Packaged: 2018-03-20 23:00:22
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,393
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3668412
Author URL: https://archiveofourown.org/users/LadyLini/pseuds/LadyLini
Summary: <blockquote class="userstuff">
              <p>When two John Does are caught in the middle of a grave desecration, it’s up to New York’s four finest detectives to figure out who they are and what they were doing.</p>
<p>(Crossover for the Supernatural and Castle fandoms)</p>
            </blockquote>





	The Usual Suspects

**Author's Note:**

> This takes place following the episode "Demon" in Castle and somewhere post-canon for Supernatural.
> 
> Disclaimer: I don’t own Castle, nor do I own Supernatural. I do not own either of the show’s characters, nor do I plan to or will I be making money off of this work.

Beckett sighed, watching the man on the other side of the glass carefully. “Do we have a name for our John Doe yet?” she asked.

“He said his name is Stan Lee,” Castle answered helpfully.

Beckett rolled her eyes. “And you believe that?”

Castle shrugged.

Beckett allowed him a small, mildly amused smile, then turned to Ryan. “How about you? Anything?”

Ryan shook his head. “CSU is running his prints though.”

“Maybe he’s an undercover CIA agent,” Castle suggested, “sent here to dig up the remains of an ancient Indian tribe because the government wants to test them for alien anomalies—”

“Castle,” Beckett snapped.

Castle closed his mouth with an audible pop. “Sorry.”

“Okay.” Beckett crossed her arms and turned away from the window to look at her team. “So we find this guy in the middle of a grave desecration—”

“Maybe he’s on that Ghosthunters show,” Castle interjected.

Beckett ignored him and lifted her coffee cup from the cabinet she’d left it on. “We find him in possession of multiple concealed firearms and weapons—”

“I’m going back to my CIA theory,” Castle decided.

Beckett glared at him. “Don’t make me gag you.”

“Kinky.” Castle grinned.

“Castle,” Beckett said in warning.

“Shutting up now,” Castle promised, reaching up to lock his lips shut with an imaginary key.

“What about his partner?” Beckett went on. “What do we know about him?”

At that, Esposito entered the observation room, waving a particularly thick file. “CSU got us a name for our John Doe,” he announced, “but I don’t think you’ll like it.”

“I never like it,” Beckett countered.

“Fair enough.” Esposito tossed her the file. “His name is Dean Winchester. Got a rap sheet a mile long too.”

“Grave desecration,” Beckett read from the file, “assault and battery, assault, breaking and entering, theft, harassment, impersonation of a federal agent,” she paused and looked up, eyes shining like they always did when they hit a breakthrough in a case, then finished, “and multiple counts of first-degree murder.”

Esposito nodded. “He’s been taken in by the cops twice, but he’s escaped both times.”

“Hang on,” Castle said, having been reading over Beckett’s shoulder. “This says he died years ag—twice.”

“The file must be wrong then,” Esposito said. “He’s sitting right there, very alive.”

“Right then.” Becket snapped the folder shut. “Anything on his partner?”

Esposito shook his head. “His partner isn’t in the system at all. Not even a parking ticket. No name, either. It’s like he doesn’t exist.”

“Maybe he’s an alien,” Castle offered.

“Not helping,” Beckett informed him.

“Oh, c’mon,” Castle pushed on. “Only an alien would wear a trench-coat in the middle of summer.”

“Fashion makes people do weird things,” Beckett retorted, handing the file back to Esposito. She turned back to the window and watched the man—Dean—for a moment. “Let’s go talk to him.”

-o-O-o-

“Mr. Winchester,” Beckett greeted him, sliding smoothly into her usual chair at the interrogation table. Castle followed closely behind, albeit not quite as gracefully. “Why don’t you sit down?”

If Dean was surprised or worried by the fact that they knew his name, he didn’t show it. “I’m fine where I am,” he retorted.

Beckett shrugged. “Suit yourself,” she said, rifling through the file. “I’m Detective Beckett with the NYPD,” she introduced herself. “This is Richard Castle.”

Dean ignored her. “Where’s Cas?”

“In holding,” Beckett replied, looking up at him. “Mr. Winchester, I have you pegged on multiple counts of just about everything in the book. If you’ll sit down, we can start talking sentences. Maybe we can come up with some sort of deal.”

At that, Dean just scoffed. “I’ll sit down when I want to.”

Beckett narrowed her eyes. “If you don’t cooperate, I can make sure you never see ‘Cas’ again,” she said mildly, as if stating the weather.

Some of the color left Dean’s face at that, but he hid it well. “Lady—”

“Detective Beckett, to you.”

Dean pinched the bridge of his nose. “Whatever,” he said.

Though he did his best to maintain his tough-guy persona, Beckett could see it slipping. “Let’s talk about your partner,” she suggested, watching Dean’s reaction carefully. 

Dean looked up, his expression hopeful. “Can I see him?”

“That depends on you,” Beckett answered. “I have some questions I want answered. You want to see your partner. I see a deal somewhere in there, don’t you?”

Dean sighed. “Dammit,” he muttered. After a moment, he seemed to have come to some sort of conclusion. “Be careful what you ask,” he warned them, taking a free seat reluctantly.

Beckett opened her mouth to begin her questioning, but Castle beat her to it. “How’d you fake your death?” he asked excitedly. “Twice, I mean.”

Dean smirked. “Danger of the job,” he answered.

“And what would ‘the job’ be?” Beckett inquired, shooting another glare at her partner.

“Saving people,” Dean responded, lips pulling up on one side. “Hunting things. It’s a, uh, family business, you might say.”

Castle leaned forward, ignoring the daggers he knew Beckett was shooting at the back of his head. “What sort of things do you hunt?”

Dean pursed his lips and shook his head. “Fifth amendment.”

“We had a deal, Winchester,” Beckett reminded him.

“Fine, then.” He leaned forward, until he was almost nose-and-nose with Castle, then spoke slowly, in a deliberate tone meant to intimidate. “I hunt the bad things. The monsters and demons. The things that go bump in the night? I’m the one that kills them. The monster under your kid’s bed? I slit its throat. I hunt things you could never even dream of.”

Castle blinked. “Wow,” he said, leaning back in his chair. He turned to Beckett and whispered, “I think he’s insane.”

Beckett nodded, letting him know she had heard him, then went on with her line of questioning. “We caught you in the middle of digging up a—” she paused and checked her file, “—Colonel Shepherd’s bones. He’s been dead since the Civil War. Can you tell me why you and your partner suddenly took such an interest in him?”

Though he wasn’t happy about it, Dean answered her question as honestly as he could. “His spirit is killing people.”

Beckett raised an eyebrow. “That’s what you’re going with?”

Dean shrugged. “I told you to be careful what you asked.”

“And how, exactly, is his ‘spirit’ killing people?” Beckett inquired, playing along.

Dean shrugged. “Hell if I know. I just gank the damn things.”

Beckett pursed her lips and pulled a picture from one of the files on the table in front of her. “Do you know this woman?” she asked, sliding the picture across the table.

Dean barely glanced at it, then shook his head.

Beckett narrowed her eyes. “Her name is Alana Murray. She was the first victim in a recent string of murders. Are you sure you don’t know her?”

“I meet lots of pretty girls,” Dean replied.

“Fine.” Beckett reached across the table and reclaimed the photograph with more force than was entirely necessary. “Where were you Thursday between seven and eight-thirty?”

Dean looked between the two of them, realizing where this was going. “Oh, c’mon. I didn’t kill her.”

Castle folded his hands, pushing his fingers together to form a shape similar to a church’s steeple. “That’s what you claim, yet you were digging up her grandfather’s bones.”

Dean blinked and leaned forward excitedly. “The colonel is her grandfather? That’s the connection?” 

“You didn’t know that?” Castle asked, his face betraying his confusion.

“Doesn’t matter,” Dean replied gruffly. “His bones were torched. It’s over.”

Beckett made a notation in one of the files. “What’s over?” she asked once she was finished.

“The killings,” Dean clarified, spelling it out like she was a kindergartener. “The colonel’s spirit killed the girl because he had gone vengeful. We burned his bones. End of story.”

Castle grinned and elbowed Beckett. “First demons, now ghosts? This just might be a sign!”

Beckett just sighed. “You’ll have to excuse my partner,” she said to Dean. “We just closed a case where the murderer claimed to have been possessed by a demon.”

At that, Dean froze. “You made an arrest?” he asked.

Beckett squinted, trying to figure why he was interested in the closed case. “Yes,” she said hesitantly.

“When?” Dean asked.

“Last week,” Beckett answered, unsure of whether or not answering his questions was a good idea.

Dean groaned. “We just finished cleaning that up,” he complained, dragging a hand over his face as if he’d just found out he was being asked to stay late to finish his boss’s paperwork. “I’ll take care of that later, I guess.” He removed his hand from his face. “Listen to the poor bastards you arrest, though. If they say they’ve been possessed—”

“Mr. Winchester,” Beckett cut him off, “I understand the necessity to set yourself up for an insanity plea, but I’d appreciate it if—”

“I’m not ‘setting myself up,’ ” Dean defended himself. “I’m just—”

Beckett held up a hand and waited for him to fall quiet. “Thank you,” she said when he did. “Now, back to business, if we may.”

Though he didn’t seem overly thrilled with the idea, Dean complied. “When will I have scored enough ‘Cop Points’ to see Cas?” he asked.

“When I say you have,” Beckett retorted. “In your file, there’s a Sam Winchester listed as one of your known associates—your brother, actually.”

Dean nodded hesitantly. “What about him?”

“His file says he died a few years ago,” Castle answered for Beckett.

“And?” Dean prompted them.

“Your file says the same about you,” Castle said. “Funny, isn’t it?”

Dean looked between the two of them. “He died in a helicopter explosion,” he said carefully.

Beckett flipped a few pages in the file. “Did your brother come back from the dead?” she asked rhetorically, pushing photographs of the two of them in a diner, each holding a machine gun, across the table. 

Dean picked up the picture and groaned. “I hate this one,” he complained, tossing it back down on the table in disgust. “They could’ve at least filmed from my good side—”

“Explain,” Beckett demanded.

Dean gave a small start, surprised by the ferocity of the command. “You want the truth?” he asked skeptically.

“That is why we’re here,” Castle replied.

Dean sighed. “Shape-shifters,” he admitted. “They take the form of—”

“All right,” Beckett cut him off, then slammed each of the folders on the table shut in turn. “I think we have enough information for now.” With that, she rose from her chair and headed resolutely for the door, Castle following her dutifully.

“Wait,” Dean called.

The interrogators paused just inside the doorway. Beckett arched an eyebrow, a clear indication for Dean to say what he wanted to say before she lost her temper completely.

Dean wet his lips uncertainly, then asked, “What about Cas?”

Beckett regarded him for a moment, as if assessing him. “We’ll see.”

-o-O-o-

“You know what’s funny?” Esposito asked the man across the table.

The man frowned, as if taking the question seriously. “Jokes,” he replied after a moment’s thought. “Like this one: why did the chicken cross the road?”

Had Ryan not been a trained homicide detective, he felt sure his jaw would have dropped.

“To get to the other side,” the man finished, as if proud to have remembered the children’s joke.

“Is this guy for real?” Esposito asked out of the corner of his mouth, the question directed at Ryan.

Ryan just shrugged.

The man leaned forward, as if to share a secret with them. “I can hear you,” he whispered. “And, yes, I am for real, though I did spend some time in a television universe.”

“Good to know,” Ryan said flatly, flicking through the open file on the table in front of him.

“So,” Esposito said, “do you have a name?”

The man nodded. “My name is Castiel,” he answered.

Ryan suppressed a chuckle. “That’s a—” He caught himself. “—unique name. Were your parents religious?”

For some reason, Castiel seemed to find this amusing. “You could say that.”

“Last name?” Ryan pushed.

Castiel frowned, as if thinking it over. “I don’t believe I have one.”

Esposito held back a sigh. “We can do this—”

“The easy way or the hard way,” Castiel finished for him. “Yes, I’m familiar with the arrangement.”

“Last name?” Ryan repeated himself.

Castiel furrowed his brow, thinking the matter over. “I think—Campbell,” he said finally. “My last name is Campbell.” He gave a small smile, as if this was some inside joke the detectives didn’t understand.

Ryan raised his eyebrows, but didn’t say anything. They could run him through facial recognition later. “Castiel Campbell it is,” he muttered, writing the name down in the file.

“Now that that’s taken care of,” Esposito said, taking the lead, “what were you doing with Dean Winchester?”

“Burning some bones,” Castiel answered easily, which surprised the detectives interrogating him. They’d expected someone affiliated with Dean Winchester to hold their cards much closer to their chest.

Ryan flipped one of the papers in the file over, gave it a cursory glance, then asked, “When did you first meet Dean?”

“Thirteen years ago,” Castiel responded promptly. “I raised him from Perdition.” He wasn’t sure why, but he got the distinct feeling that, had he been there, Dean would have face-palmed at his answer.

Esposito glared at the ceiling. “And what does that mean?”

“I—” Castiel tilted his head to the side, as if confused. “I believe it’s rather obvious. Dean went to Hell—he was kill by some Hellhounds—, and I, along with the rest of my garrison—”

“Your garrison?” Esposito interrupted.

“Of angels,” Castiel clarified. “Anyway. We were sent to rescue Dean, because he was the Righteous Man and we needed him to start the apocalypse—”

This time, it was Ryan that interrupted. “The apocalypse?”

Castiel nodded. “But Dean showed me a different path. I rebelled for him. And, I suppose I should mention that we did end up stopping the apocalypse, but—”

“Hold up,” Esposito cut him off. “Are you telling me that the apocalypse happened?”

“Quite a few times since then, actually,” Castiel said with a nod.

Esposito gritted his teeth and set about changing the topic. “What do you know about Alana Murray?”

Recognition flitted across Castiel’s face. “She was his first victim,” he answered.

“Whose first victim?” Ryan asked, picking up on the key word.

“Colonel Shepherd’s,” Castiel replied. “Who else’s?”

“Right,” Esposito said sarcastically. “But, see, your partner told our friends the same thing. We ran his name, and there’s a little problem with that theory.”

“And that is?” Castiel inquired, expression startled. He looked like someone had just told him that his favorite basketball team had not, in fact, won last night’s game like he’d thought.

“Colonel Shepherd is dead,” Ryan stated bluntly.

Castiel squinted at him. “Of course he is.”

Esposito sighed. “Then how could he be the murderer?”

Castiel tilted his head again. “He’s a spirit… I believe that much is obvious.”

“Why would it be obvious?” Ryan asked, scribbling something on a spare sheet of paper.

“I thought…” Castiel faltered. “Aren’t you hunters?”

“Hunters?” Esposito repeated.

“Oh.” Realization of some sort dawned upon Castiel’s face, and his entire demeanor changed. “Where’s Dean?” he demanded.

“With our friends,” Esposito said bluntly. “What about the second victim—Sheila Montgomery?”

Castiel had clammed up, though, and showed no signs of cooperating again. “I’m done talking.”

Ryan sighed. “C’mon, dude, you’ve gotta—”

At that, Castiel snapped. In much the same manner that he had demanded to know where the pie was all those years ago, Castiel lurched forward across the table, grabbed Esposito by the collar, and demanded to know where Dean Winchester was.

-o-O-o-

“Do you really think that’s a good idea?” Ryan inquired dubiously.

Beckett leaned back on the side of her desk. “What other choice do we have?” she countered. “They won’t talk otherwise.”

“Yeah, but—” Esposito gestured at the whiteboard, indicating the list of charges against Dean Winchester. “—do we really need them to?”

“Dean? No,” Beckett admitted. “But this Castiel guy doesn’t have any priors—he’s not even in the system—, so if we’re going to convince a jury that him being in the grave with Dean wasn’t a one-time thing…”

Castle lifted a hand cautiously. “But if we put those two in a room together—”

“What’s the worse that could happen?” Beckett asked rhetorically. “They’ll be locked in, there’ll be guards, we’ll be watching…”

“I don’t like it,” Esposito admitted, crossing his arms absently while he studied the board.

“Why not?” Ryan asked.

“Because,” Esposito said, “these guys have escaped more prisons than most people can name.”

“So?” Ryan prompted him.

“The trench-coat guy is an alien,” Castle put in. “Aliens have all sorts of cool superpowers.”

“Thanks for the tip,” Beckett muttered wryly. 

Castle grinned. “Any time.”

-o-O-o-

“You sure about this?” Esposito asked, watching Dean Winchester stare at the tabletop through the two-way mirror.

“Not at all,” Beckett replied, “but either way, this is going to be interesting.”

A moment later, the group watched as Castiel was shoved into the interrogation room with Dean, handcuffs fastened securely around his wrists. An unceremonious “you have ten minutes” was uttered, then the door was slammed and locked behind him.

“Here we go,” Ryan muttered, more to himself than anyone else.

Dean promptly jumped up from his chair, not seeming to care that he’d knocked it over, and enveloped Castiel “Campbell” in a hug. “Thank God,” he murmured, stepping back to give the other man, still in his trench-coat, a once over.

“I’m certain God had nothing to do with it,” Castiel quipped.

“It’s a—” Dean started.

“Figure of speech,” Castiel finished. “I know.”

Dean grinned at that, and his very being seemed to relax now that he knew his partner was all right. “Are you okay?” he asked, eyeing the handcuffs suspiciously. 

Castiel shrugged. “They’re a bit tight, but—”

Dean took that as his cue to step forward and grab the handcuffs in question, his back to the window, effectively shielding them from view.

Castiel seemed startled by the sudden advance. “What are you—”

“Shut up,” Dean replied. “There,” he said after a moment. There was a jingling sound, then the handcuffs hit the floor. “Better?”

“Much,” Castiel said.

Beckett felt her jaw drop open. “What the hell?”

Around her, she could feel a similar state of confusion and awe overtake the other occupants of the observation room.

Ryan blinked incredulously. “How did he do that?”

“He’s an alien,” Castle declared. “I knew it!”

“I told you this was a bad idea,” Esposito muttered, heading for the door with his gun drawn.

Ryan and Beckett moved to follow him, but Castle called them back. “Look,” he said, pointing through the window with a smirk.

Ryan’s eyes went wide. “That is so not PG.”

Castle seemed to be the only one unsurprised by the “activities” going on in the interrogation room. “Maybe that’s how aliens communicate.”

Beckett rolled her eyes. “Let’s go show them how people communicate then,” she retorted, giving her gun a pointed wave.

Seconds after the four left the observation room, the speakers emitted a sound akin to flapping wings.

-o-O-o-

“Put your hands where I can see them!” Beckett roared, the door to the interrogation room pounding open behind her. Ryan and Esposito filed in behind her, ready to provide the muscle, should it be needed. Castle stood in the doorway, ready, in true Castle-form, to observe.

Immediately upon entering the room, Beckett froze. “What the hell?” she echoed her previous statement.

Ryan looked around in confusion. “Did we—”

“This is the right room, isn’t it?” Esposito asked, turning in a small circle.

Beckett nodded, though she was beginning to have doubts. “This is the right room,” she affirmed.

Castle piped up, still in the doorway, “Then where did they go?”

Esposito bent over, looking under the table in vain. “They were making out in here two seconds ago,” he said in disbelief, narrowly avoiding smacking the back of his head against the bottom of the table as he straightened. 

“People don’t just disappear,” Ryan retorted. “There’s got to be something…”

Beckett opened her mouth, expecting some logical explanation to flow forth, but nothing came. 

Their suspects had disappeared.


End file.
